Front Matter

Chapter 13 Evaluation and Rehabilitation Options for Orthopedic Disorders of the Canine Thoracic Limb 345

Common injuries by tissue type

There are five types of tissues that may sustain
injury and can be treated by the therapist: muscle/
tendon, ligament, intra‐articular structures (menis-
cus and cartilage), joint capsule, and bone. A com-
prehensive understanding of the physiological
mechanisms of healing for each tissue must be
incorporated into the treatment plan, allowing
the therapist to determine whether the course of
healing is following a normal physiological path
or if reassessment and change in treatment plan
are required (see Chapter  3 for more details).
Table 13.2 provides an outline of treatments per

tissue type, and Table 13.3 an outline of treatment

guidelines.

Muscle injuries

Muscle is comprised of a contractile component—

the muscle fibers—and an elastic component con-

sisting of connective tissues and tendon. When

the muscle voluntarily contracts, the connective

tissues absorb and dissipate the energy of the con-

traction allowing for smooth and supple move-

ment (Nordin & Frankel, 1989). When the muscle

passively elongates, the elastic components elon-

gate first followed by the musculotendinous junc-

tion (Wright et al., 1982). Understanding these

mechanical properties of muscle assists a thera-

pist in determining if one or both of the muscle

components is involved in the injury. Treatment is

initiated on the correct muscular component(s)

with the treatment plan including rehabilitation

of the entire muscle and all compensatory issues

related to the primary injury.

Three types of muscle injuries are commonly

seen—surgical injuries, strain injuries (i.e.,

tendinitis), and chronic extensibility injuries

(i.e., tendinosis). Surgical incisions may cause

damage to the contractile component or the

elastic component of the muscle. Determining

which tissue is involved requires an anatomic

understanding of the surgery. Acute treatment

of surgical incisions includes modalities and

soft tissue retrograde massage to decrease

edema. Subacute treatment includes modalities

to increase circulation and promote tissue heal-

ing followed by scar massage to correctly align

collagen fibers. Chronic treatment requires

returning the soft tissues to their previous

strength while addressing compensatory issues

related to the primary injury (Table 13.3).

External injuries to muscles in the form of

loads exceeding the inherent force of the mus-

cle causing strain injuries can affect the contrac-

tile or elastic components. Differentiating the

components requires an assessment of active

muscle contraction in descending order of mus-

cle tension produced (Norkin & Levange, 1983),

concentrically, isometrically, and eccentrically,

with observation of joint position that may

place the elastic components on stretch. For

example, assessment of possible biceps injury

may test a foot shake (concentric), single limb

Table 13.2 Common thoracic limb diagnoses per
tissue type

Diagnosis Primary injury tissue type

Biceps tendinopathy Muscle, elastic, and/or

contractile components

Carpal hyperex-

tension

Ligament

Muscle, elastic, and/or

contractile components

Carpal bone

subluxation

Ligament

Fragmented coro-

noid process (FCP)

Bone

Cartilage

Joint capsule

Muscle, elastic, and/or

contractile components

Infraspinatus

contracture

Muscle, elastic, and/or

contractile components

Medial shoulder

syndrome

Ligament, grade I, II, or III

Muscle, elastic, and/or

contractile components

Osteochondrosis

dessicans (OCD)

Cartilage

Supraspinatus

tendinopathy

Muscle, elastic, and/or

contractile components

Teres major strain Muscle, elastic, and/or

contractile components

Ununited anconeal

process (UAP)

Bone

Cartilage

Joint capsule

Muscle, elastic, and/or

contractile components